1. Field of the Invention
The present invention relates, in general, to cooking machines and, more particularly, to a microwave oven which cooks foods using microwaves.
2. Description of the Related Art
As is well known to those skilled in the art, a microwave oven heats food by radiating microwaves of a frequency of 2450 MHz generated from a magnetron onto the food. When the microwaves oscillate food molecules, heat is generated due to a collision of the food molecules, and the food is then cooked by the heat.
FIG. 1 is a block diagram of a conventional microwave oven. As shown in FIG. 1, a control unit 102 that controls an entire operation of the conventional microwave oven has an internal memory 102a therein. The internal memory 102a stores operational data (for example, algorithmic data and/or HELP data) and/or cooking data required to perform various cooking modes. An input terminal of the control unit 102 is connected to an input unit 104 and an external memory 106. On the input unit 104, cooking mode selection buttons and/or numerical buttons are mounted to allow a user to select cooking modes or cooking times. The external memory 106, which is a storage device to supplement the internal memory 102a of the control unit 102, stores the cooking data of respective cooking modes. An output terminal of the control unit 102 is connected to a magnetron driving unit 108, a fan driving unit 112, a tray motor driving unit 116 and a display driving unit 120. The magnetron driving unit 108 drives a magnetron 110 to generate microwaves. The fan driving unit 112 drives a cooling fan 114 to cool various electrical devices mounted in a machine room (not shown) of the conventional microwave oven. The tray motor driving unit 116 drives a tray motor 118 to rotate a cooking tray (not shown) in a cooking cavity (not shown). The display driving unit 120 drives a display unit 122 to display, for example, HELP data, cooking information and preset values for cooking modes.
If a new cooking mode is added to the conventional microwave oven, cooking data and (operational) data relating to the new cooking mode must be added. In this case, if the internal memory 102a of the control unit 102 used in the conventional microwave oven is a Read Only Memory (ROM) supporting only reading of data, update of the data is not possible, so the data relating to the new cooking mode must be stored in the external memory 106. However, the conventional microwave oven is designed such that the external memory 106 is limited to a storage of the cooking data of respective cooking modes. For example, the external memory 106 of the conventional microwave oven stores the cooking data, such as a cooking time and an output value of a magnetron according to an amount of the food in each of the cooking modes. Consequently, if the cooking mode is newly added, a burden is generated in that a new control unit must be developed to store additional operational data of the added cooking mode in the internal memory 102a of the new control unit.